The present invention is generally directed toward a gastrostomy device and, more particularly, toward an internal bolster for such a gastrostomy device.
Several different gastrostomy designs have been developed and employed over the years. Each of these designs has met with varying degrees of success. One of the main reasons for this varying success is the competing and sometimes conflicting design and functional requirements of gastrostomy devices. Firstly, gastrostomy devices should be easy to install within a patient, both for an initial installation and subsequent replacements. Secondly, the gastrostomy device should have an internal bolster which will resist withdrawal forces to prevent inadvertent partial or complete removal of the internal bolster from the patient via the stoma tract. These design considerations tend to conflict with each other since gastrostomy devices which are easily installed have heretofore had undesirably low resistance to withdrawal forces, and gastrostomy devices which provide suitable resistance to withdrawal forces have been difficult or expensive to install and/or replace.
One popular known gastrostomy device, sometimes referred to as a dome-PEG device, is illustrated in FIGS. 1a-1b. The dome-PEG device 10 has a tubular portion 11 with an integral internal bolster 12. The internal bolster 12 has a flat, annular wall 13 radially surrounding an opening 17 of the tubular portion 11 and a curved ring-shaped wall 14 that extends away from the periphery of the annular wall 13 in a direction opposite to the tubular portion. A distal end 15 of the internal bolster defined by the ring-shaped wall 14 provides a circular opening 16 through which material from the tubular portion opening 17 may flow.
An initial or first dome-PEG device 10 is installed in a patient via the esophagus and stomach. The tubular portion 11 is pulled through an incised tract until the annular wall 13 of the internal bolster abuts the stomach lining surrounding the incised tract. As such, the tubular portion extends from the patient""s body and may frictionally receive an external bolster to retain the dome-PEG device in place.
An installed dome-PEG 10 is removed from the patient either via the esophagus or by pulling on the tubular portion to overcome the internal bolster""s resistance to withdrawal and thereby deforming and pulling the internal bolster through the stoma tract. A subsequent or replacement dome-PEG device is installed identically to the initial or prior dome-PEG device, i.e., via the esophagus.
Accordingly, dome-PEG devices offer the advantage of the satisfactorily high resistance to withdrawal forces while suffering from the disadvantage of requiring installation via the esophagus, which is rather time-consuming for the physician and uncomfortable for the patient.
An alternative to the dome-PEG is commonly known as a stick-PEG, and is exemplified by U.S. Pat. No. 5,007,900, the disclosure of which is expressly incorporated herein in its entirety. The ""900 patent device includes a resilient tube having a distal end with a transversely directed internal bolster. The internal bolster has a pocket radially spaced from the tube and adapted to receive a rod. The rod permits proper orientation of the internal bolster and, more specifically, urges the bolster to a stretched position collateral with the tube to facilitate installation of the stick-PEG device within a patient.
Stick-PEG devices are generally installed in existing stoma tracts and are used as replacements for dome-PEG devices due to the former""s relatively easy method of installation. However, stick-PEG devices suffer from the disadvantage that, in the minds of some clinicians, the internal bolster surface area may be insufficient to prevent flow of stomach contents around or under the internal bolster. Therefore, there is concern about leakage around the internal bolster and migration of fluid up the tube-tissue interface. Also, medical personnel responsible for installation have indicated some dislike for the manipulation required to install stick-PEG devices within a patient. These disadvantages have limited the acceptance of stick-PEG devices as an alternative to dome-PEGS.
Various other types of PEG devices, and internal bolsters, are known in the art. For example, U.S. Pat. Nos. 4,311,148 and 4,668,225 show feeding tubes or catheters having resilient wing-like protrusions about the end of the tube for retaining the tube within a passage through the wall of a body cavity. The tube is designed to be inserted into the patient through a fresh incision that is then sutured about the tube. To remove the tube from the patient, it is possible to pull the tube through the passage by exerting sufficient force to fold the wings back out of the way.
U.S. Pat. No. 4,573,576, the disclosure of which is expressly incorporated herein in its entirety, shows a catheter with a disk-like retainer on one end. A line is introduced through an incision in the patient""s skin, fascia and stomach wall, and an endoscope is used to capture the loose end within the stomach and to draw it out the patient""s mouth. The line is then used to draw the tube portion of the catheter out through the incision. An endoscope is also used to remove the catheter.
U.S. Pat. No. 4,863,438, the disclosure of which is expressly incorporated herein in its entirety, shows a catheter that may be inserted into an established stoma from outside the body. A hollow mushroom-shaped resilient head on the tube may be distended by the insertion of a rigid obturator into the tube, with the distended head acting as a dilator to facilitate passing of the catheter through the stoma. Once the head clears the stoma, the obturator is withdrawn, and the head expands. A similar process is employed to remove this device, or mechanical traction may be used to remove the device.
In the gastronomy devices known in the art, the internal bolster generally has a planar wall which engages the patient""s internal surface. In order to provide the desired resistance to withdrawal forces, the internal bolster is generally not compliant or pliable and, due to the arcuate shape of internal body tissues, typically has only point or line contact with the underlying tissue surface (i.e., stomach wall). As such, any withdrawal forces are concentrated on a limited portion of the subjacent tissue, and irritation and potential tissue deterioration and necrosis is a constant concern. Moreover, too much force or pressure on a limited area of tissue may damage the tissue, and may result in leakage around the gastrostomy device, ulceration, improperly fitting gastrostomy devices, and, ultimately, failure of the stoma.
Therefore, there exists a need in the art for an improved internal bolster for gastrostomy devices. Moreover, there exists a need in the art for a gastrostomy device internal bolster which is compliant and which interfaces in a more comfortable and anatomically correct fashion with the patient tissue internal surface. Finally, there is a need in the art for a gastrostomy device that is easily and quickly installed and that has an internal bolster which provides satisfactory resistance to withdrawal forces to prevent unintended removal of the bolster via the patient""s stomach.
The present invention is directed toward a gastrostomy device which is easy to install within a patient and which includes an improved internal bolster. The present invention is also directed toward a gastrostomy device internal bolster which is compliant and which interfaces in a more comfortable manner with the patient. The present invention is further directed toward a gastrostomy device which is easy to install and which provides sufficient resistance to withdrawal forces.
In accordance with the present invention a gastrostomy device includes a tubular portion having an inner end and an outer end. An internal bolster extends radially from the tubular portion inner end. The internal bolster can be presented in either an installation configuration or a deployed configuration. In the installation configuration the internal bolster is elastically deformed or bent to be generally in-line with an axis of the tubular portion. Presentation of the internal bolster in the deployed configuration permits insertion of the gastrostomy device, i.e., internal bolster and tubular portion, through a patient""s existing stoma. In the deployed configuration the bolster extends radially from the inner end of the tubular portion and generally transverse to the tubular portion axis.
In further accordance with the present invention, in the installation configuration a rod member extends generally parallel to the tubular portion. A projecting end of the rod member extends past the inner end of the tubular portion and is received within a pocket defined by the internal bolster. The internal bolster has a first part and a second part, the second part including the pocket. The first and second parts are preferably on relatively opposite sides of the tubular portion.
In further accordance with the present invention, a suture member extends through the rod member and includes a first portion and a second portion. The first portion projects from an outer end of the rod member. The second portion from the rod member projecting end and is operable to bind the first part of the internal bolster to the tubular portion.
In further accordance with the present invention, the internal bolster radially surrounds the tubular portion and has an inner surface and an outer surface. The inner surface faces the tubular portion, while the outer surface is directed away from the tubular portion. The outer surface includes the pocket. The inner surface is curved or arcuate such that the inner surface is relatively convex. The outer surface has a relatively planar portion surrounding the opening of the tubular portion and an arcuate portion surrounding the planar portion. As such, the internal bolster has a varying thickness which advantageously results in a variable flexibility.
In further accordance with the present invention, the internal bolster is relatively compliant or pliable to ease installation of the gastrostomy device and to reduce irritation following installation, while being sufficiently rigid to provide the necessary resistance to withdrawal forces. The internal bolster is formed from a material having a thickness, flexibility and shape to permit substantially full contact between the patient""s tissue and the convex inner surface of the bolster.
In addition to the aforementioned device, the present invention is also directed toward a method for assembly and installation of the device.